1. Field of the Invention:
The present invention relates to metallurgical process vessels, in general, and to tuyeres for bottom blown furnaces, basic oxygen furnaces (BOF's), in particular.
2. Description of the Prior Art:
Several types of devices are known for introducing gases into the inner volume of metallurgical process vessels. The most common ones of these devices include: (a) tuyeres--either single annulus, annulus-tube (AOD), or single tube, (b) porous plugs, and (c) solid refractory blocks which are either machine bored or etched. A problem with existing tuyeres, porous plugs, etc. which are installed in the bottom of metallurgical process vessels is that they have no positive way of opening and closing on demand. Gas must continuously flow through these devices to keep them open and operational. An advantage exists, therefore, for devices that can be opened or closed to allow the flow of gas as it is required, without detrimental plugging or fouling occurring in the devices. By providing the flow of gas only as required, such devices will make the most economical and efficient use of the gas.
It is therefore an object of the present invention to provide a new type of device which will permit or stop the flow of gass to the bottom of metallurgical vessels, such as BOF's on demand.
It is a further object of the present invention to provide a device of such rugged contruction having a service life comparable to existing tuyeres, porous plugs, etc.
Still other objects and advantages will become apparent from the attached drawings and description of the invention presented hereinbelow.